The present invention relates to a semiconductor laser having an active layer and an optical waveguide layer coupled with each other at a high efficiency and a method for manufacturing such a semiconductor laser.
A semiconductor laser of the type having an active layer and an optical waveguide layer formed as a unitary structure with each other is promising because it is adaptable to an integrated optics laser and an optical integrated circuit in which a plurality of optical active elements are coupled with one another via an optical waveguide. As a structure in which the active layer and the optical waveguide layer are coupled with each other at a high efficiency, a BJB (Butt-Jointed Built-in) structure is described in detail by Mr. Abe et al in Electronics Letter, Vol. 17, No. 25, 1981, pp. 945-947. The BJB structure has such a construction that the butt-joint system for optical fiber splicing by butting together their cores is applied to a semiconductor laser.
However, since the conventional BJB structure involves two liquid growth steps, the yield rate is relatively low.